import { useState, useEffect } from 'react'

/**
 * const scrollRef = useRef(null)
 * const [x, y] = useScroll(scrollRef)
 * @param {*} scrollRef ref对象 DOM对象
 * @return {*} [x, y]
 */
const useScroll = (scrollRef) => {
  const [pos, setPos] = useState([0, 0])

  useEffect(() => {
    function handleScroll(e) {
      setPos([scrollRef.current.scrollLeft, scrollRef.current.scrollTop])
    }
    scrollRef.current.addEventListener('scroll', handleScroll, false)
    return () => {
      scrollRef.current.removeEventListener('scroll', handleScroll, false)
    }
  }, [])

  return pos
}

export default useScroll
